Topic: Drag N Drop nearly there!

I have drag and drop working nicely in Firefox and Safari - but not IE!  Where it works fine the first time and then sulks!

In the source for the page, for the 25 or so droppables (each with a different id) you get

//<![CDATA[
Droppables.add("appt_time2007070509001000", {hoverclass:'hover',
onDrop:function(element){new Ajax.Updater('all_change', '/diff/appointments/dragndrop?drop_time=2007070509001000',
{asynchronous:true, evalScripts:true,
parameters:'id=' + encodeURIComponent(element.id)})}})
//]]>

And for the 25 or so Draggables you get
//<![CDATA[
new Draggable("appt_id166", {scroll:true})
//]]>

When the drag and drop is complete, the page refreshes using
session[:render_layout] = false

Using Firebug, I see that it has run all the Droppables.add and now has 100 entries in Droppables.  And if I do another drag n drop, it has 150!  I've tried to find a way to clear the Droppable and Draggable entries at the start of the refresh but so far without success - any ideas?  Or any other reason why IE might not work?

Cheers Mike